Hair cutting apparatus

ABSTRACT

This invention relates to improvements in apparatus for cutting hair. The invention employs a novel hair cutting means which in the embodiment illustrated comprises a pair of cutting blades, one formed as a sheath within which the other blade is contained. Perforations in the wall of the sheath blade are arranged to admit the ends of the hairs to be cut into the interior of the sheath where the second blade, which has helical cutting edges, cooperates with the sheath to effect a shearing action.

Unite States Patent H 1 1 3,731,379

Williams May 8, 1973 [54] HAIR CUTTING APPARATUS FOREIGN PATENTS 0RAPPLICATIONS [76] Inventor: Reed F. Williams, 4522 East Chap- 634,9072/1962 Ital l ..30/29.5 man, Orange, Calif. 92667 1,451,856 7/1966France 30/295 [22] Filed: 1971 Primary Examiner-Robert C. Riordon [2]]Appl. No.: 209,164 Assistant Examiner-J. C. Peters [57] ABSTRACT [52]U.S. Cl ..30/29.5 51 int. Cl. ..B26b 19/06 relates m apparatus forcutting hair. The invention employs a novel hair ..30 295,415,435, [58]Flew of Search 30/43 6 cutting means which m the embodiment illustratedcomprises a pair of cutting blades, one formed as a sheath within whichthe other blade is contained. Per- [56] References Cited forations inthe wall of the sheath blade are arranged UNITED STATES PATENTS to admitthe ends of the hairs to be cut into the interior of the sheath wherethe second blade, which has 2,026,630 1/1936 Harris ..30/29.5 X helicalcutting edges cooperates the heath to f 2,243,441 5 1941 Russell 30/416x fem a Shearing action, 2,946,121 7/1960 Marach i ..30/29.5 3,027,6354/1962 Frith ..30/43.5 5 Claims, 4 Drawing Figures W/////////// I IPAIENTEB 8W MENTOR REED F. WILLIAMS HAIR CUTTING APPARATUS Thisinvention relates to improvements in apparatus for cutting hair and itrelates particularly to a hair cutting implement capable of cutting hairbrought into contact with it from any radial direction towards the axisof its cutting parts.

In addition to other applications which will hereinafter be apparent,the invention is particularly useful in providing a hair clipper orshaver for cutting hairs growing from the walls of nostrils and earcanals. Accordingly, an object of the invention is to provide a novelhair clipping and shaving device useful for trimming hairs in nostrilsand in ear canals and to do it safely and efficiently and to do it in amanner which insures that cut hairs will be expelled from the nostril orthe ear canal. The need for the device in this application extends tohumans and to animals and another object of the invention is to providea hair clipper which can be embodied in a single structural designuseful in its application to either humans or animals.

Another object of the invention is to provide a hair clipping devicehaving a cutting head which is generally tubular in form and which iscapable of cutting hairs directed to the cutting head from any radialdirection. Another object is to provide such a hair cutting or shavingimplement which is readily produced, easily serviced and which is easyand convenient to use.

These and other objects and advantages of the invention which willhereinafter appear are realized in part by the provisions of means forcutting hairs in response to the application of motive power and meansfor applying motive power to the cutting means, the cutting meansincluding a pair of blades each having a cutting edge capable ofcooperating to shear off hair extending between the cutting edges as oneis moved over the other, one of said blades comprising a tubular sheathhaving openings formed through its wall of size to accommodate hairs andopening at the interior surface of the sheath at sharply definedinteriorcutting edges and the other blade of which is disposed within thesheath, the means for applying motive power comprising means for movingthe second blade relatively to the sheath to carry the cutting edge ofthe second blade over the interior surface cutting edges of the sheath.

One embodiment of the invention has been selected for illustration inthe drawings. The embodiment shown vis currently preferred. However,various modifications may be made in the embodiment shown and otherembodiments of the invention are possible without departing from thespirit of the invention or the scope of the appended claims.

In the drawings:

FIG. 1 is an isometric view of a hair cutting implement embodying theinvention;

FIG. 2 is a cross-sectional view of the apparatus of FIG. 1, taken on aplane extending through the longitudinal axis of the unit except thatcertain of the elements having symmetrical shape have not beensectioned;

FIG. 3 is a transverse cross-sectional view showing the arrangement ofthe switch employed in the apparatus of FIGS. 1 and 2; and

FIG. 4 is a transverse cross-sectional view, shown enlarged, showing fanemployed in the preferred embodiment of the invention.

Referring to FIG. 1 of the drawing, the shaving implement there shown isdesignated 10 and it comprises a casing which is generally cylindricalexcept that its forward section is frusto-conical. A cutting head ismounted upon and extends axially from the frustoconical end of theshaver and an electrical power cord extends along the axis of the casingfrom its other end. As best shown in FIG. 2 of the drawing, the forwardsection 12 of the casing has threaded connection to the rearward section14 of the casing at the forward end of the latter. The rearward end ofthe rear section 14 is closed by a rotatable end structure 16 which, aswill be explained below, comprises part of an electrical switch.Electricity is introduced into the housing by a connector plug 18 whichcooperates with a male plug carried by the closure member 16. The haircutting head 20 is symmetrical about its center axis which is coincidentwith the axis of the casing and is mounted upon the frusto-conicalsection 22 of the forward casing section 12.

The invention comprises cutting means for cutting hairs in response tothe application of motive power. This cutting means comprises a pair ofblades each one of perforations which has a cutting edge and the twoblades are capable of cutting hairs as an incident to shearing action inwhich the cutting edge of one blade moves relatively over the cuttingedge of the other blade. In the invention, one of these blades comprisesa tubular sheath having perforations formed through its side walls bywhich the hairs to be cut are admitted into the interior of the sheath.A sharp edge is formed at the juncture of the interior wall of thesheath with the walls that define the perforations through the sheath. Aplurality of perofrations are provided and a cutting edge is formed atthe opening of each of these into the interior of the sheath. The secondblade is mounted at the interior of the sheath and is rotatable aboutthe axis of the interior wall of the sheath so that its cutting edgemoves over the cutting edges of the sheath. The second blade rotates butits rotation may occur as complete revolutions or as an oscillatorymotion. When the second blade oscillates it is advantageously providedwith a double shearing edge to provide a shearing action during bothphases of its oscillatory motion. In such a case the shearing edges ofthe sheath are advantageously formed about the entire periphery of thesheath wall margin that marks the opening of the perforations into theinterior of the sheath. When the second blade revolves, or when thesecond blade oscillates but is expected to provide a shearing actionduring only one phase of its oscillatory motion, the perforationsthrough the sheath need form a cutting edge at only one side of theperforation openings and the second shear need have only one shear edgeassociated with each blade or blades.

The shearing edge of the second blade may lie in a single radial planeextending through the axis of blade rotation and it may comprise anumber of such blades arranged in parallel. Advantageously, however, thecutting edge of the second blade is formed as a helix extending aroundthe axis of the blade rotation. The preferred embodiment incorporatesthis feature because it serves a useful function in helping to disposeof hair trimmings.

In the preferred form of the invention, selected for illustration in thedrawing, the cutting head comprises a first blade 24 having the form ofa sheath containing the second blade 26. The sheath is tubular in form.it is cylindrical except at its forward end which is domeshaped andclosed. The rearward end is open. A series of parallel helical grooves28 extend in parallel around the sheath from a point near to, butremoved from, the rearward edge of the sheath to a point at the forwardend of the sheath where they terminate to circular connecting structure36. At its rearward portion the srr is unperforated and this sectionserves as a collar 3 which the sheath is mounted upon the frusto-conicaisection 22 of the casing. The spiral grooves or slots extend entirelythrough the side wall of the sheath They could be formed as circularopenings or they could be helical in form but of shorter length beinginterrupted by cross supports to lend rigidity to the unit. Openings ofthis form, and in fact of any form which will admit the ends of hairs tobe cut to the interior of the sheath, are contemplated within theinvention. However, the preferred form, and the one selected forillustration in the drawings, contemplates helical perforations whichextend from a point near the rearward end of the sheath entirely aroundthe sheath to a terminus at the forward support 30. Thus formed, thestructure can be likened to a number of connecting strips helical inform about the axis of the unit and extending from the collar at one endto the disk at the other. it will be apparent from examination of FIGS.l and 2 that the end disk 30 can be rotated relatively to the collarsection 32 in a direction to tighten the helixes comprising theconnecting strips 34 thereby to reduce the inside diameter of thesheath. The sheath is made of resilient material whereby the interiorwall of .the sheath 2 has a given diameter in relaxed condition. Thediameter can be increased by unwinding the helical strips 34 againsttheir bias. The inner blade 26 has an outer diameter very slightlylarger than the inside diameter that the sheath has in its relaxedcondition. When the sheath is assembled over the second blade 26 theconnecting strips 34 are made to unwind slightly. The renitence of thestrips 34, thus stressed, tends to make them squeeze against the innerblade 26.

The inner blade is provided with two opposed helical cutting edges 36and which extend over its length within the sheath 24 and the sheathsqueezes against these cutting edges with very light pressuresufficient, nonetheless, to provide a very effective shearing actionwith the edges formed at the interior of the sheath by the juncture ofthe inner wall of the spiral strips 341 and the side walls of thesestrips which define the spiral recesses 28. While the pressure withwhich the sheath 24 squeezes upon the inner blade 26 is-very light,means are advantageously provided for preventing frictional forcebetween the two blades from effecting rotation of the sheath 24 as thesecond blade 26 is rotated as hereinafter described. The means by whichthe sheath is prevented from rotation is best seen in FIG. ll. At itsforward end the truncated conical end 22 of the implement casing iscastillated and the rearward end of the sheath 24 is castillated incomplementary form to the end that projections 52 from the casing fitwithin notches formed in the collar portion 32 of the sheath 24 andprevent relative rotation between the two.

The forward end 22 of the casing tenninates in a tubular section 40extending axially forward from the section 22 and having outsidediameter to form a press fit within the collar portion 32 of the sheath24. The sheath is assembled with the casing section 22 by sliding thetubular portion 40 within the open end of the sheath such that theprojections 42 are disposed within the corresponding notches formed inthe rearward edge of the sheath 24. Casing section 12, and thefrustoconical section 22 formed integrally therewith, is hollow.However, at in forward end it is provided with a sleeve Whose axis iscoincident with the axis of the casing. The sieeve 48 is connected by aspider to the tubular section All). its inner diameter accommodates therearwardly extending drive shaft d6 of the second blade at. The sleeved8 forms a bearing for rotation of the shaft 46.

Means are provided in the invention for applying motive power to thecutting means in the form of means for moving the second bladerelatively to the sheath to carry the cutting edge of the second bladeover the interior surface edges of the sheath. In the embodiment shown,the motive power means is effective to rotate the helical cutting blade26 within the sheath 24. To this end means are provided for applyingforces to rotate the shaft 46. In this embodiment the motive means iseffective to make the shaft revolve. Advantageously, as shown, themotive means comprises an electrically powered motor coupled to theshaft 46. In FIG. 2 the motor 54) is disposed within the interior of therear section M of the casing of the implement W. The interior of thecasing has size to accommodate the motor and it is provided withconformations in its walls, such as the shoulder 52, by which the motoris held in proper position. Motor output is taken at output shaft 54which revolves upon an axis coincident with the axis of the casing andof the second blade 26 and its shaft 46. Means are provided for couplingthe shaft 54 of the motor 5'0 to the drive shaft as. in the embodimentselected for illustration in the drawing, this means comprises a shaftextension 56. The extension 56 extends through an axial bore at theforward end 58 of the easing section id. The margins of this bore form abearing for rotation of the shaft extension. The forward end of theextension is provided with a key 61) which interlocks with acorresponding notch in the lower end of the blade shaft 4-6.

The motor shaft is formed to fit within an opening in the lower end ofthe shaft extension 56 to form a driving connection. Thus, the motorshaft may, as shown, be made square in cross-section to fit within asquare opening in the lower end of the shaft extension. At its lower endthe shaft extension is enlar ed to form a spring gland by which toretain a compression spring as which is trapped between this springgland and a spring glanddd carried upon the shaft 545. The function ofthe compression spring 62 is to force the shaft extension 56 upwardly sothat its key h ll is retained within the cooperating slot at the lowerend of shaft as to maintain the driving connection. in addition, spring62 forces the inner blade 26 upwardly against the disk end 310 of thesheath 241 to maintain the cutting surfaces of the blade in engagementwith the forward, closed end 30 of the sheath. The thrust forces aretaken by the end disk 31D and no thrust bearing is required at sleevedill or at the end wall 5% of the casing section 114.

In a preferred form of the invention means are provided for expellinghair clippings from the interior of the cutting head 20. This meanscomprises a means for causing a movement of air through the cutting headto an exit point at one end. In the embodiments selected forillustration two structures are provided both of which perform thisfunction. Because of the helical shape of its cutting edge, the innerblade 26 serves to force air movement towards the open end of the sheath24 when the inner blade is rotated. This air is free to move downwardly,in FIG. 2, past the spider 44 by which the sleeve 48 is mounted upon thecasing. Passing through the spider 44 the air enters the interior of theforward section 12 of the casing from whence it may exit via a series ofperforations 66 which extend around the periphery of the forward section12. To augment the action of the helical cutting edges of the blade 26 amultiple bladed fan 68 is provided. In the embodiment shown the fancomprises four blades extending laterally outward from a central hub70.,The hub is bored so that it may be press'fitted upon the shaft 46.When forced over the blade shaft 46 the hub '74 will rotate with theshaft and serves to retain the inner blade 26 in assembled conditiondespite removal of the sheath 24 for any reason. Advantageously, asshown, the hub 70 has length sufficient to extend over the connectionbetween shaft 46 and shaft extension 56. This arrangement assures thatthe shaft and shaft extension will remain in alignment with the key ofone fitting within the notch of the other and without the need for amore complex locking conformation. This construction is shown incross-section in FIG. 4.

Advantageously, as shown, the helix shaped strips 34, which form thesheath 24, advance in the same direction as the cutting surfaces of theinner blade 26. The pitch or the rate of advance of the inner bladehelix is advantageously different from the pitch or rate of advance ofthe helixes associated with the sheath 24 less binding occur. It isadvantageous that they advance in the same direction as shown so thatthe frictional forces between the two are not permitted to tend tounwind the strips 34 that comprise the outer sheath 24.

Means are provided for applying electrical energy to the motive means 50and a preferred form of this means is illustrated in FIGS. 2 and 3 ofthe drawing. At its rearward end the rearward section 14 of the casingis provided with an annular recess formed on its interior surface. Thisrecess is designated by the numeral 80 in FIG. 2. The end closure 16 ofthe casing is provided with an annular rib on its exterior surface whichfits within that groove 80. Portions of the casing and end closure arecut away to permit assembly of the end closure with the casing and theend closure is retained in position by a detent means not shown. Thecentral rear face of the end closure 16 is provided with a recess whichextends partly through the end closure member and is oblong incross-section. This recess accommodates the oblong shaped, femaleconnector 18 at the end of an electrical cord 84. A male connector,comprising two L-shaped members 86, is assembled with the end closure 16so that one arm of each member 86 extends through the end closurerearwardly in parallel into the recess where they are spaced forengagement with the connector 18. The other arm of each of the L- shapedmembers 86 is disposed on the forward face of the end closure 16. Thetwo arms extend in opposite directions with their outer ends projectingforwardly from the forward face of the end closure 16. The motor 54} isprovided with two input terminals at its rearward end. These terminals$8 are arranged opposite one another on the rear face of the motor inposition for engagement by the outer end of the inner arms of the twoconnector members 86 in one rotational position of the end member lidrelative to the casing I14. The arms of the connector members 86 havesufficient resilience to maintain electrical contact with the terminals88, when rotated to engage them. To facilitate rotation of the enclosure 16 and effect switch action, its rearward face is provided witha pair of projections 90 which permit the application of finger pressureto accomplish switching.

Although we have shown and described certain specific embodiments of ourinvention, we are fully aware that many modifications thereof arepossible. Our invention therefore is not to be restricted except insofaras is necessitated by the prior art and by the spirit of the appendedclaims.

I claim:

1. Hair-cutting apparatus comprising in combination, a generallycylindrical casing, electrically energizable motive power means in saidcasing, means connected to said casing for conducting electrical energyto said motive power means, a housing including a frusto-conical sectionconnected to one end of said casing and formed with a plurality ofangularly spaced radial openings, a generally cylindrical sheath mountedon the reduced end of said frusto-conical housing and formed with aplurality of helically-shaped slots through which human hair can extend,an inner blade rotatably mounted within said sheath to cooperatetherewith to shear said hairs, power transmission means interposedbetween said motive power means and said inner blade comprising a shaftrotatably mounted in said housing and having one end operativelyconnected to said inner blade and a rotatable output shaft in saidcasing having one end drivinglyconnected to said motive power means, animpeller mounted on said first named shaft to rotate therewith, andspring-loaded coupling means interconnecting the other ends of saidfirst named shaft and output shaft comprising a coupling element on saidoutput shaft engageable with said first named shaft and a compressionspring interposed between said motive power means and said couplingelement to urge the latter into engagement with said first named shaft.

2. l-iaircutting apparatus according to claim ll wherein said couplingelement is formed with a key on the end thereof and said housing shaftis formed with a slot for receiving said key to effectively interconnectsaid first named and output shafts.

3. Haircutting apparatus according to claim 2 wherein said inner bladeis formed with a helical cutting edge for cooperation with thecylindrical sheath. 1

4. Hajrcutting apparatus according to claim 3 wherein saidfrusto-conical housing and said casing are formed with mating fasteningthreads for engagement and disengagement thereof.

5. Haircutting apparatus according to claim 4 wherein said couplingelement is slideably mounted on said output shaft, and means is providedfor limiting travel of said element in response to the force of saidcompression spring.

1. Haircutting apparatus comprising in combination, a generallycylindrical casing, electrically energizable motive power means in saidcasing, means connected to said casing for conducting electrical energyto said motive power means, a housing including a frusto-conical sectionconnected to one end of said casing and formed with a plurality ofangularly spaced radial openings, a generally cylindrical sheath mountedon the reduced end of said frusto-conical housing and formed with aplurality of helicallyshaped slots through which human hair can extend,an inner blade rotatably mounted within said sheath to cooperatetherewith to shear said hairs, power transmission means interposedbetween saId motive power means and said inner blade comprising a shaftrotatably mounted in said housing and having one end operativelyconnected to said inner blade and a rotatable output shaft in saidcasing having one end drivingly connected to said motive power means, animpeller mounted on said first named shaft to rotate therewith, andspring-loaded coupling means interconnecting the other ends of saidfirst named shaft and output shaft comprising a coupling element on saidoutput shaft engageable with said first named shaft and a compressionspring interposed between said motive power means and said couplingelement to urge the latter into engagement with said first named shaft.2. Haircutting apparatus according to claim 1 wherein said couplingelement is formed with a key on the end thereof and said housing shaftis formed with a slot for receiving said key to effectively interconnectsaid first named and output shafts.
 3. Haircutting apparatus accordingto claim 2 wherein said inner blade is formed with a helical cuttingedge for cooperation with the cylindrical sheath.
 4. Haircuttingapparatus according to claim 3 wherein said frusto-conical housing andsaid casing are formed with mating fastening threads for engagement anddisengagement thereof.
 5. Haircutting apparatus according to claim 4wherein said coupling element is slideably mounted on said output shaft,and means is provided for limiting travel of said element in response tothe force of said compression spring.